Order-enhanced silver nanowire networks fabricated by two-step dip-coating as polymer solar cell electrodes†
The efficient utilization of Ag NW by avoiding their aggregation and multi-layer stacking in their networks can improve the optical and electrical properties of the derived transparent conductive electrodes (TCEs). In this work, we develop a two-step dip-coating process to prepare Ag NW networks on polyethylene terephthalate (PET) substrates using three types of Ag NW with length/diameters (L/D) ratio of 100, 400 and 1000 respectively. The NW with small or medium L/D (100 and 400) are likely to form order-enhanced networks since they are rigid and easy to be separated. The TECs prepared by this approach present much higher performance than those prepared by spray coating. The optimal Ag NW-based TCEs show a typical sheet resistance of 35 Ω sq−1 with high transparency of 92%. The polymer solar cells constructed on the resulting TCEs can give an efficiency of 3.28%, demonstrating the potential application of our Ag NW/PET films as the ITO alternative in flexible solar cells.